Speed-reduction gearing



July 8, 1930. w. HEAP El AL 1,770,035

7 SPEED REDUCTION GEARING Filed Sept- 1928 2 Sheets-Sheet 1 Jul 8, 1930. I w, HEAP ETAL 1,770,035

SPEED R EDUCT ION GEARING Filed Sept. '7, 1928 2 Sheets-Sheet 2 Patented July 8, 1936 I mural) STATES PATENT oF cs WALTER I-IEAP, or mvnnroon, WILLIAM GEORGE :aEAnor r nnsoo'r, JAMEs BA N S,

or LIVERPOOL, Ann enonen nnLsoN nsnmonn, or WATE -Loo; ENGLAND srnnn annocrzon GEARING Application filed September a; was, Serial No. 304,578, and inGreat Brit'ainSeptember 9, 1927.

This invention relates to speed reduction gearing of the'kind in which an eccentric secured, to a driving shaft, or the like,'has loosely mounted upon it an, externally toothed wheel which engages an internally toothed wheel secured to a driven shaft, or the like, on the same centre line as said driving shaft; and spaced stationary pins orstuds extending through holes provided in u said externally-toothed wheel: so that'when said driving shaft is rotated the externallytoothed wheel gyrates and causes the rotation of ghe' internally-toothed wheel and driven sha t. i

toothedwheel shall be evenly distributed and the loading ofthe teeth of the gearing relatively low. 1

The gearing of our lnventlon s characterized by the employment of a plurality of co centrics which are appropriately set on the driving shaft or the like, an externallyii toothed wheel mounted loosely on each eccentric, and a single internally toothed wheel with which all of said externally-toothed wheels engage in balanced disposition.

we will further describe our invention so with the aid of the accompanying sheet of centric (Z is loosely mounted an externally- P bracket Z), and whereto eccentrics c, Z,-set

1n diametrical oppos1t1on-are, respectively,

secured by means of keys 6, 6

On said eccentric c is loosely mounted an externally-toothed wheel. f, and on said ectoothed' Wheel 9: Said externally-toothed wheels 7, g mesh with diametrically opposed teeth of an internally-toothed wheel h which is sufliciently wide to receive both of said externally-toothed wheels 7, g.

Our invention has for its object to provide gearing of the type referred to in which the stresses on the outputi. e. internally Said internally-toothed wheel h is secured I to a plate j bymeansiof bolts 70, said plate 1 j beingprovided with a boss y' rwhich is se cured by key 6 to a driven'shaft zones; same centre lineas thedriving shaft. ;A bracket m, carries saiddriven'shaft Z.

Said bracket 6 carries four round pinsn. positioned on diameters atrightangles to 7 each other. In each of said externally toothed wheels f, g are four circular, holes 0, 0 respectively, through which holes said pins 71 extend, said holes being larger in diameter than the pins by the differencejbfetween the diameters of the "internally; toothed wheel It and the externally-toothed wheels f, g. Said pins, being stationary, are

adapted to resist rotary motion of the externally-toothed wheels f, g whilst permitting same to gyrate. i

The whole of the gearing is enclosed ina liquid-tight casing 29 which is filled with oil so that all parts are lubricated, the eccentrics 0, (land pinsn being lubricated by the aid of the oil passages g. a 7

In operation, said driving shaft-a is m tated by any suitable means and at any desired speed, and the consequential rotation ot the eccentrics 0, d' causes said externally.-

toothed vvheels f, g to gyrate around thesta tionary resistance pins Such gyration of the externally-toothed wheels f, g'causes the rotation of the internally-toothedv wheel vh, H

' and so the driven shaft-Z rotates in the same stresses on said latter wheel are evenly. dis

tributed and the tooth load of the gearing is relatively low.

The ractical advantages of the constructlon and arrangement before described,

are i 1. The gearing occupiesismall spacein res lationto the 'powercapable of being trans mitted. V 2. The even distribution of loading or nallytoothedWheelfh, the loading or torque o a wires torque'stresses on; said internally-toothed Wheelensures steady transmission of power.

a 3. As the gearing is at alltimes in balance,

its acquisition of periodic or sympathetic 1 vibrations is obviated V I V e '14. The comparativelyfllow tooth loading results in substantialreduction in the so 7 called .flakingiefof the teeth. 5

In the example ofgearing illustrated saich internally-toothed wheel it is provided with 44teeth and externall I toothedwheels g are each provided witi'42 teeth; consequently the eccentrics: '0, d (i. 79. 13116 driving shaft a) will make twenty two revolutions to one'of the drivenjshaftl. "In other words,

the angularmovement of the internallytoothed wheel h: is 16. 36 degrees i for each complete revolution" of the driving shaftayfl r number of teeth of the respective toothed wheels be varied so will the ratio of a reduction be altered. For instance, if the g externally-toothed wheels are, provided with" provided with; 421 teeth, the reduction ratio willbe eleventoone;

driven shafts.

40 teeth and the internally-toothed Wheel is "It "be oted that 7 the externally-if toothedwheels f, g gyr'ateand the internally-jtoothed wheel h rotates around .a common a:

'centre which-ifs that of both driving and ures.

.It ist o be clearly un derstoodthat we do not confine our invention to the precise form of embodiment hereinbeiore described, as va-- riouschanges or modifications may be made to meet differing conditions or circumstances centric and held to 'gyratory motion Within a limited range during movement of the drlve, shaft, sald gears having suitably spaced openings wheremto correspondingly arranged. stationary pins extend and walls of'which openings define the gyratory limits of the gears, an annular gear common to the gyratory gears, a support for the annular gear said support'being carried by the driven shaft and arranged to locate the gear teeth pathof travel of the'annular'gear as concentric with thedriven shaft axis, said support and annular gear being located within and spaced from the Walls ofthe casing; said support having openings adapted to permit passage of lubricant intothe open atingzoneof theeccentrics and the gyrating andannular gears, said annular gear support openings-beinglocated to deliver lubricant to said gyrating gear openings and to lubrieating ductsin-the gyrating gearsto feed lubricant to the eccentric surfaces and to thetooth zone of thegears, whereby the annular gear will be advanced by the intermittent activityof the teeth of the gyrating gears with the activity made manifest concurrently at 'SYIIllIlGQIiCELllfY-difil)088d points without departingfrom its spirit and scope. i

As instances of constructional variations, the 7 number of eccentrics "and gyrating externally-toothedQwheels operated thereby may be increased, the internally-toothed Wheel be- T ing; ofcourse appropriatelywidened to accommodate the gyrating wheels'which will beeq'ui-spaced' in relation to said internallytoothed wheel in order to maintain the ance. "And/or the number'of stationary re:

sistance pinsn, orthe like, and correspond ing holes in the med."

gyrating wheels may be va- What We claim as our invention and de sire to secure LettersPatent is Asa means fortransmitting rotary motion between axially alined drive and driven shafts under [lubrication 'bath conditions with'the shaft movement in similar direc- 1 tions and with a speed reduction characteristic, a stationary lubricatiomcarrying casing carrying axially-alined spaced apart "bearingstosupport the drive and driven shafts respectively, airially-alined' drive and driven V shafts extending into the space between the bearings, a succession of symmetrically-dis:

posed eccentrics on the drive shaft within the space a gear'for andcarried by eachec;

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